Automated pipetting apparatus having a combined liquid pump and pipette head system

Abstract

The technology described herein generally relates to systems for extracting polynucleotides from multiple samples, particularly from biological samples, and additionally to systems that subsequently amplify and detect the extracted polynucleotides. The technology more particularly relates to microfluidic systems that carry out PCR on multiple samples of nucleotides of interest within microfluidic channels, and detect those nucleotides. The technology still more particularly relates to automated devices for carrying out pipetting operations, particularly on samples in parallel, consistent with sample preparation and delivery of PCR-ready nucleotide extracts to a cartridge wherein PCR is run.

What is claimed is: 
     
       1. An automated pipetting apparatus comprising:
 a controller; 
 a gantry comprising a horizontal rail; and 
 a liquid dispenser moveable vertically within a container to make contact with the liquid therein and configured to carry out suck and dispense operations therein, the liquid dispenser comprising a mechanical connection to the horizontal rail of the gantry and moveable along the gantry, the liquid dispenser comprising:
 a plurality of pumps; 
 a plurality of dispense heads, each dispense head configured to receive gas from a respective one of the plurality of pumps; and 
 electrical connections configured to transmit control signals from the controller to the plurality of pumps, the control signals controlling operation of each dispense head by controlling when to reduce gas pressure in one of the plurality of dispense heads, thereby causing a sucking operation, and controlling when to increase gas pressure in one of the plurality of dispense heads, thereby causing a dispense operation, the controller programmed to simultaneously actuate individual pumps of the plurality of pumps to dispense individual fluid volumes, at least one of the plurality of dispense heads configured to dispense a different fluid volume than the fluid volume simultaneously dispensed by at least one other dispense head, 
 wherein the mechanical connection to the horizontal rail and the electrical connections to the controller are the only external connections to the liquid dispenser. 
 
 
     
     
       2. The automated pipetting apparatus of  claim 1 , wherein no gas lines connect the plurality of pumps to the gantry. 
     
     
       3. The automated pipetting apparatus of  claim 1 , wherein every dispense head of the plurality of dispense heads receives gas from its respective pump and dispenses fluid without gas being directed to any other pump or its respective dispense head. 
     
     
       4. The automated pipetting apparatus of  claim 1 , wherein the liquid dispenser comprises four pumps and four dispense heads, and wherein each head is configured to accept a pipette tip. 
     
     
       5. The automated pipetting apparatus of  claim 4 , wherein the liquid dispenser comprises a sensor configured to detect when a pipette tip is positioned on a dispense head, and wherein the automated pipetting apparatus further comprises one or more sensors configured to sense when vertical motion of the liquid dispenser is obstructed. 
     
     
       6. The automated pipetting apparatus of  claim 1 , configured to aspirate and dispense fluid in connection with analysis or preparation of solutions of two or more samples. 
     
     
       7. The automated pipetting apparatus of  claim 1 , wherein the liquid dispenser is configured to move in three dimensions. 
     
     
       8. The automated pipetting apparatus of  claim 1 , wherein the plurality of dispense heads are individually sprung. 
     
     
       9. The automated pipetting apparatus of  claim 1 , wherein no solution of a sample enters the plurality of dispense heads during normal operation of the dispenser. 
     
     
       10. The automated pipetting apparatus of  claim 1 , configured to aspirate, in a single operation, an amount of 1.0 ml of fluid or less, the automated pipetting apparatus further configured to dispense, in a single operation, an amount of 1.0 ml of fluid or less. 
     
     
       11. The automated pipetting apparatus of  claim 1 , configured to aspirate, in a single operation, an amount of fluid in the range 10 n1-1 ml, the automated pipetting apparatus further configured to dispense, in a single operation, an amount of 10 nl-1 ml of fluid or less. 
     
     
       12. The automated pipetting apparatus of  claim 1 , further comprising at least one of an individual pipette tip sensor, an encoder for the one or more pumps, a force sensor, a barcode sensor, and an image sensor. 
     
     
       13. The automated pipetting apparatus of  claim 1 , wherein the one or more pumps each comprise a plunger configured to compress or uncompress a volume of gas. 
     
     
       14. The automated pipetting apparatus of  claim 13 , wherein the controller is configured to independently control movement of each plunger to regulate gas flow to each of the plurality of dispense heads independent of gas flow to any other dispense head. 
     
     
       15. The automated pipetting apparatus of  claim 1 , wherein the liquid dispenser further comprises a printed circuit board configured to control operation of the plurality of pumps. 
     
     
       16. The automated pipetting apparatus of  claim 1 , wherein the controller is programmed to simultaneously actuate individual pumps of the plurality of pumps to aspirate individual fluid volumes, the fluid volume aspirated by at least one dispense head different from the fluid volume simultaneously aspirated by at least one other dispense head. 
     
     
       17. The automated pipetting apparatus of  claim 1 , wherein the controller is programmed to simultaneously vent individual pumps of the plurality of the pumps. 
     
     
       18. A method of dispensing a liquid using the automated pipetting apparatus of  claim 1 , the method comprising:
 moving the liquid dispenser from a first position to a second position through the mechanical connection to the horizontal rail of the gantry; 
 transmitting a control signal from the controller to the plurality of pumps via the electrical connections; and 
 independently regulating the flow of gas from each of the plurality of pumps to a respective one of the plurality of dispense heads. 
 
     
     
       19. The method of  claim 18 , wherein independently regulating the flow of gas comprises independently moving a plunger in each of the plurality of pumps to compress or uncompress a volume of gas. 
     
     
       20. The method of  claim 19 , wherein independently controlling a plunger comprises transmitting a control signal from the controller to a motor in each of the plurality of pumps. 
     
     
       21. The method of  claim 18 , wherein regulating gas flow to a dispense head corresponds to sucking a solution of a sample out of a container.